This study proposes to investigate theoretically and expeimentally the information processing capabilities of the human visual system. In particular, the role of a presumed first level of associative memory will be probed with psychophysical techniques. To accomplish this objective, theoretical predictions for neural models of associative memory are being sought. A particular prediction has been identified which indicates that humans may be confused by mixed sets of subsets of equivalently named visual stimuli. Psychophysical techniques using a computer controlled tachistoscope and reaction time measures are being developed to probe for this confusion.